This invention relates to cabinets, parts of cabinets prior to final assembly and to methods of forming cabinets and, in particular, to insulated refrigerator cabinets and methods of forming same.
At present the construction of domestic refrigerators, particularly the cabinets, are commonly made from a formed steel exterior, which is either pre-painted or post-painted, into which a thermoformed plastic interior is placed locating in a roll formed edge. A steel or plastic base is attached to the bottom and top of this assembly along with a back panel of similar materials to create a closed cavity between the exterior and interior. This assembly is placed into a jig that supports the walls of the cabinet whilst insulation is injected and expanded into the cavity. Associated with this type of construction are additional processes that seal the joints between the individual parts in order to prevent the expanded foam from leaking.
U.S. Pat. No. 4,580,852 shows a refrigerator incorporating a cabinet of this type. The major drawbacks with this type of construction and manufacturing process are the number of individual parts, processes, and their associated costs. In addition to this the processes are time consuming and labour intensive.
U.S. Pat. No. 5,374,118 assigned to Whirlpool Corporation shows a refrigerator cabinet wherein the side walls and top are formed by twin-wall thermoforming as a single part. They are folded and a back is fitted to the cabinet to support them in position. The back of the cabinet incorporates the refrigeration system. While this system offers a significant improvement over the prior art, difficulties are perceived with the overall cabinet space occupied by the refrigeration system carrying back unit and with difficulties of connecting and sealing the back unit to the remainder of the refrigerator cabinet.
It is therefore an object of the present invention to provide a cabinet and or parts thereof and or a method of forming same which will go some way towards overcoming the above disadvantages or will at least provide the public with a useful choice.
In one aspect the invention consists in a refrigerator cabinet comprising:
a twin walled insulated plastic member divided, by a plurality of elongate seams at which said twin walls contact, into three or more wall sections disposed sequentially in a side by side relation, said member folded at said seams such that said sequence of wall sections form three or more sides of a cabinet connected at said elongate seams, said sides defining a refrigeration space there between,
a top end cap connected to the top edge of said wall member retaining said wall member in said folded configuration, said top end cap enclosing the top end of said refrigeration space,
a base plinth connected to the bottom edge of said wall member retaining said wall member in said folded configuration, said base plinth supporting, directly or indirectly, mechanical components of said refrigeration system, and
floor means, integral with or separated from said base plinth, to enclose the bottom end of said refrigeration compartment.
In a still further aspect the invention consists in a refrigerator including a refrigerator cabinet as described above, a door mounted on said refrigeration cabinet to enclose the front side of said refrigeration space and thereby fully enclose said refrigeration space, and a refrigeration system to refrigerate said refrigeration space, at least a part of said refrigeration system being mounted on said base plinth.
In a still further aspect the invention consists in a method of forming a refrigerator cabinet comprising the steps of
(a) thermoforming a twin walled insulated plastic member divided, by a plurality of elongate seams at which said twin walls contact, into three or more wall sections disposed sequentially in a side by side relation.
(b) folding said plastic wall member along each said seam to form three or more sides of a cabinet connected at said elongate seams, said sides defining a refrigeration space therebetween, and
(c) fitting a top end cap to said cabinet to retain said wall member in said folded configuration and enclose the top end of said refrigeration space, and
(d) fitting a base plinth to the bottom edge of said wall member to retain the bottom edge of said wall member in said folded configuration.
In a still further aspect the invention consists in a refrigeration cabinet formed by a method in accordance with one or more of the above paragraphs.
In a still further aspect the invention consists in a cabinet including:
a twin walled plastic member divided, by a plurality of elongate seams at which said twin walls contact, into three or more wall sections disposed sequentially in a side by side relation, said member folded at said seams such that said sequence of wall sections form three or more sides of a cabinet connected at said elongate seams, and
a top and or a bottom end cap, having generally an interior and an exterior face and having on the inner face along at least two sides thereof at or adjacent the periphery thereof a recessed channel, the top and/or bottom edge respectively of said folded plastic wall member fitted into said channel or channels, said channel or channels retaining said wall member in said folded configuration.
In a still further aspect the invention consists in a cabinet for an appliance including a wall member formed by twin sheet thermoforming, said wall member incorporating a plurality of panels, said panels connected to one another by one or more joined edges where said twin sheets contact to form a seam, and in said appliance said wall member being in a folded condition along one or more of said seams such that said plurality of panels form a plurality of walls of said appliance, being, as a group, differently configured to when said wall member was initially thermoformed, wherein one or more of said folded seams do not coincide with the corner between walls of said appliance that correspond to the panels joined by the respective folded seam.
In a still further aspect the invention consists in a cabinet for an appliance including a wall member formed by twin sheet thermoforming, said wall member incorporating a plurality of panels, said panels connected to one another by one or more joined edges where said twin sheets contact to form a seam, and in said appliance said wall member being in a folded condition along one or more of said seams such that said plurality of panels form a plurality of walls of said appliance, being, as a group, differently configured to when said wall member was initially thermoformed, at at least one said seam said twin walled plastic member having essentially an inner facing sheet and an outer facing sheet, and said member is formed adjacent at said seam such that in said folded condition said inner facing sheet contacts itself, said contact being between portions thereof on opposite sides of said seam and spaced from said seam, said contacting portions being fused to one another.
In a still further aspect the invention consists in a wall member formed by twin sheet thermoforming including one or more seams where said twin sheets contact, said wall member adapted to be folded at one or more of said seams to form a plurality of walls, characterised in that at least one said seam is intended to be folded through a set angle, and that at least one said sheet of said twin sheets includes, at or substantially at said seam, a transition between surfaces thereof which is the complement of the said set angle, such that if said seam is folded through said set angle, said surfaces will be substantially continuous across said seam.
In a still further aspect the invention consists in apparatus for preparing a twin sheet thermoformed wall member, including one or more seams at which said wall member is to be folded bringing included faces of said wall member at said seam together, for folding comprising a heat conductive head having a heating face configured to contact along said seams to be folded at, means to heat said heat conductive head, said head supported on a support means, which, together with a support means associated with said wall member is adapted to bring said head heating face into contact with said seam and by that contact allow the transfer of heat from said head to said seam and thereby soften said seam for folding.
In a still further aspect the invention consists in a cabinet for a refrigerator substantially as herein described with reference to and as illustrated by FIGS. 1 to 5 of the accompanying drawings.
In a still further aspect the invention consists in a cabinet for a refrigerator substantially as herein described with reference to and as illustrated by FIGS. 6 and 7 of the accompanying drawings.
In a still further aspect the invention consists in a method of forming a refrigerator cabinet substantially as herein described with reference to and as illustrated by the accompanying drawings.
In a still further aspect the invention consists in a cabinet for an appliance including a corner arrangement substantially as herein described with reference to and as illustrated by FIG. 9 of the accompanying drawings.
To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.